The invention relates to a fuel injection pump with a cam drive which operates the fuel supply stroke of at least one pump piston. The pump includes a housing within which a part of the cam drive is mounted. The cam drive also has a revolving part, and the cam part within the housing is adjustable relative to the revolving part for the purpose of adjusting the initial point of the fuel injection by means of an adjusting piston which is acted upon with an rpm-dependent pressure, and which is movable against a reset force.
In a known fuel injection pump without a hydraulic initial point of injection the possibility exists of manually adjusting the injection point to "early". In the lower load and rpm range this fuel injection pump has no automatic injection point adjustment, so that this arbitrary change occurs in the range that is not covered by the automatic adjustment. In the higher load and rpm ranges the adjustment occurs mostly dependent on the load, since a linkage that is hinged on the arbitrarily activated adjusting lever of the governor serves as the connecting member between the rpm governor and the injection adjuster. Aside from the fact that the beginning point of injection is here dependent on the load, this device is indeed adjustable to "early" in the lower rpm and load ranges, but is generally turned off. Precisely in this rpm range, however, the beginning point of injection has a decisive influence on characteristics of the combustion, such as noise, poisonous gases, and fuel consumption.